Smokeless propellant powder



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TY L. DAVIS 9F SOMERVILLE, MASSACHUSETTS.

SMO Y 3 E Drawing.

To all whomit may concern:

I Be it known that l Tanner L. DAVIS, a citizen of the Unitedtates, anda resident of Somervillc, county of Middlesex, and Stateof'Massachusetts, have invented an Improvement in Smokeless PropellantPowder, of"

which the following is a specification.

The subject of this invention is smokeless proplellant powder.

T elmain objects of the invention are the production of a powder havingthe ballistic advantages of colloided nitrocellulose powders while atthe same time possessing perfect stability and which may be p paredwithout the useof volatile and hyg oscopic solvents thereby renderingthe powder nonhygroscopic and constant in its ballistic properties andwhich may be so combined that the rate and temperature of combustion maybe regulated to any desired degree.

Pentaerythrite tentranitrate or tetranitropentaerythrite, as it iscommonly but incorrectly called, is an excellent explosive which hasfound considerable use in detonators, detonating fuses, etc. It is avery powerful explosive, being somewhat more powerful thannitroglycerine.

It is Very hot and for this reason'perhaps, has found little applicationforuse in fire arms. Like nitro glycerine it contains more oxygen thanis needed for its own combustion, and like nitroglycerine it can submitto being mixed with other substances, either explosive or nonex'plosive,which contain an amount of oxygen, for the preparation'of mixtures whichare. suitable for use either as shattering explosives or as propellantpowders. Q

'lPentaerythrite te'ntranitrate exists in the form of white crystalswhich while sensitive to shock and friction, are nevertheless perfectlystable in themselves an'd'do not decompose spontaneously, as donitrocellulose and nitroglycerineewith the evolution of acid producingoxides of nitrogen. The

great stability. of ,the substance renders it especially suitable forthe preparation of perfectly stable smokeless powder. The

' high temperatureand rapid rate of combustion of pentaerythritetetranitrate make it desirable that this substance should not be usedalone as a propellant owder but should be incorporated or mixe with someother i substances which will diminish the rapidity of its burning andlower its temperature 0% combustion. 'Such propellant mixturesinsuiiicient' ss rnoirntnanr. rownnn.

. Application filed. April 16, 19 21. Serial EmeSL BvQO.

at best wouldbe somewhat coarse and their time of burning and theconsequent ballistic properties could not be regulated as precisely ascan now be done with colloided nitrocellulose powder. The best materialfor the purpose will be one which forms with pentaerythrite a uniformhomogenous' mass sufiiciently plastic to be molded or squeezed intoperfectly solid and non-porous powder grains.

Since'pentaerythrite is a tetrabasic alcohol it forms in addition to thetetranitrate, a whole series of other derivatives, esters and others,similar to those which are formed by any of the alcohols. derivativeswith the aromatic aldehydes. Being a tetra-basic alcohol it formsderivatives in which one, two, three or four of the hydroxyl groups. aresubstituted in the same or different ways.

I have discovered that certain derivatives of pentaerythrite form withpentaerytbrite tetranitrate homogenous mixtures which, sometimes in thepresence of solvents and It forms cvstalline sometimes not, are plasticand can conveniently be molded. I have found, for instance,

that pentaerythrite tetrabenzoate is suitable taery t-hrite tetranitrateand an ester of pentaerythrite.

3. A propellant powder, comprising a plasticised pentaerythrite.

4. A propellant powder, comprising pentaerythrite tetranitrate and abenzoate of pentaery'thrite.

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5. A propellant powder comprising pentag I erythrite tetranitrate andpentaerythrite tetra-benzoate.

6. A propellant powder, comprising a plasticised pentaerythritederivative.

7. The process of producing a smokeless propellant powder comprisingmixingpeutaerythrite derivatives, at least one ofwhich taerythritederivatives, at least one of which possesses explosive properties to'form a possesses explosive properties, in the presence plastic mass andthen dividing said plastic of a solvent to form a plastic mass, and then10 mass into grains of the desired shape and dividing the plastic massinto grains of the 5 size; desired shape and size.

8. The process of-produing a smokeless propellant powder, comprisingmixing pen= TENN EY L. DAVIS.

